Error code reference

Trane Hvac Error Code E3

Test mode indicator showing the system is operating in test mode.

Trane codes Trane hvac codes

Test mode indicator showing the system is operating in test mode.

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Step-by-step tests with expected resistance, voltage, and continuity values
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E3 on my Trane HVAC

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Test mode indicator showing the system is

From Service Manual 376952, p.44:

1.Access service mode to confirm the active fault code and read stored error history.

2.Measure control board supply voltage at the test points. Expected: 12 VDC and 5 VDC; a drop below 4.75 VDC on the logic rail points to a failed onboard regulator.

3.Inspect all connectors on the main control for corrosion, thermal stress, or backed-out pins. Reseat each connector with the power disconnected.

Part WPW10804018

Electronic control board

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Get the full diagnostic procedure for E3.

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